1. Field of the Invention
The present invention relates generally to the field of endodontics and more specifically to a method for preparing a gutta percha coated carrier used in obturating an extirpated root canal.
2. Description Of The Related Art
Current methods of obturating (filling) an extirpated (stripped) root canal commonly involve packing a root canal with a thermoplastic material, such as gutta percha, so that the root canal space is filled with the thermoplastic material. Preferably, the space is filled with the thermoplastic material forming a seal which prevents leakage between the root canal and the surrounding tissue.
It has been found that a satisfactory seal can be formed by softening the gutta percha by heating it prior to inserting it into the root canal. Normally, the gutta percha is applied to a carrier prior to insertion into the root canal in order to facilitate insertion. Carriers pre-coated with gutta percha are known, as shown by U.S. Pat. No. 4,758,156 issued on Jul. 19, 1988 to the inventor of the present invention and which is incorporated herein by reference. However, carriers pre-coated with gutta percha are expensive to purchase, and a less expensive means is desired for applying gutta percha to a carrier.
U.S. Pat. No. 5,067,900 issued Nov. 26, 1991 to inventor, McSpadden, teaches an inexpensive method of applying gutta percha to a carrier. The McSpadden patent teaches use of a syringe whose barrel is pre-filled with sufficient gutta percha to coat a plurality of carriers. According to the teachings of McSpadden, the amount of gutta percha applied to a carrier is dependent on the forca exerted on the plunger of the syringe and upon the rate of withdrawal of the coated carrier from the discharge end of the syringe. One problem with this method is that the person coating the carrier must be steady-handed in order to obtain a uniform and consistent coating of the carrier. Steady handiness is difficult with the McSpadden device since the entire syringe body is hot due to the preheating necessary to increase the plasticity of the gutta percha.
Also another problem with multiple usage syringes, such as the McSpadden syringe, is that if the carrier is inserted into the root canal to test the sizing fit prior to applying the gutta percha to the carrier, as is the common practice, it may be coated with debris that could contaminate the community pool of gutta percha of the syringe.
The present invention provides a reliable, easy to use, and inexpensive method for applying a uniform coating of gutta percha to a carrier without contamination problems, as it employs a single dosage, disposable source of gutta percha.